A real-estate lock box is shaped to be secured to a doorknob or other structure attached to a property. The lock box contains a key to a home, apartment, office or other locked portion of real estate property. To obtain the key, a user of the lock box uses another manual key, a security code or a swipe card to open the lock box and obtain the key to the property. The property can then be accessed using the key to the property. After accessing the property, the key is returned to the lock box to be available for the next user.